Lock-stitch sewing-machine.



L taken partially along mirra s'rnrns ra creme.

LAURENCE E. TOPHAIVI, OF SWAMPSCOTT, MASSACHUSETTS, ASSEGNO?.- TO UNITED SHOE MACHINERY COMPANY, OF '.PTERSON, NEVI JERSEY, A. CORPORATION 0F NEW JERSEY.

LQCK-STIT CH SENIN G-.L ICHINE.

Patented Jen. 5, i935.

Appuaaon aiearrarh iii, 1913. serial Nn. 754,214.

To all uhm/i it may concern:

Be it l'aown that I, LAURENCE Haar, a iii' en of the United States, at Swampscott, in the county of Essex and State of Massachusetts, haveinvented certain new and useful Improvements in Lock- Stitch Sewing-lilachines; and l do hereby declare the following to be a Jfull', clear, and exact description ot' the invention, such .as

E. Torvwill enable others skilled in the art to which rotates.

With the above object in View, invention consists in the lock stitch sewing machine hereinafter described and particularly pointed out in the claims.

In the drawings which illustrate the preferred embodiment of the present invention, Figure- 1 is a plan View Fig. 2 is a section the line 2-2 of Fig. 1; andFig. 3 is a section taken partially along the line 3-3 of Fig. 1.

1n the illustrated embodiment of the in` vention, the loop or" thread drawn down by a hook needle is cast around the bobbin case 1 by means of a rotary hook, indicated gen` erally by reference numeral 2. The hook comprises an annular body portion 3 and an inwardly directed thread-engaging beak 1 which enters the loop of thread drawn down by the needle and takes it from the barb of the needle. The annular body portion 3 oit thehook has at its lower end an inwardly projecting liange 5 `which is engaged in an annular raceway formed between the body of the hook supporting trame 6 and a plate 7 secured to the top of the support. The hook makes three revolutions to each reciprocation of the needle and is continuously rotated in timed relation therewith by means of a bevel gear wheel 10 which meshes with bevel gear teeth 11 cut in the peripheriv oft the annular hook body 3. rl`he barbed needle (not shown) passes upwardly through the passage 12 in the hoolr supporting frame t5 and plate 7 and through the anresiding the presenty nular body of the hook and draws down thiouglrthe throat-plate oi' the machine a loop of thread which is entered by the beak 4. T he loop of thread taken from the needle by the beak 4- slips into the thread-receiving groove 8 of the hook which acts to spread the loop of needle thread and carry it about the bobbin case 1. The hook support 6 is a. trarne of a. substantially U-shaped outline haring two legs 15 and 16 in the ends of which are formed co-aXial bearings 17 and 18 by means of which the hook supporting frame 6 is hinged to the frame of the machine.- The hook supporting frame 6 is given a limited oscillation about the axis of the bearings 17 and 18 once for every reciprocation of the needle so that the beak e will pass to the left, as viewed in Figs. 1 andi?, of the needle and thus clear the needle during the two idle rotations of the hook. The gear wheel 10 is mounted to rotate on a shaft 20 which is rigidly held in the supporting frame 6 and held in place by means of the nut 21. At the end of the hub 22 of the gear wheel 10 is formed a universal joint 23 throu h which the power is transmitted "from a `gear Wheel 2'mounted to rotate upon a shaft 25 fixed to the machine frame. The universal'lioint 23 lies in the axis of the bearings 17 and 18 and permits a limited oscillatory movement of the hook supporting frame 6.

The above described parts have substantially the same construction and mode of operation as the corresponding parts illustrated and described in my co-pending applications for sewing machines, Serial No. 621,286, tiled April 15, 1911, and for lock stitch sewing machines, Serial No. 698,458, led May 20, 1912.

The bobbin case 1 is discoidal in outline and is rotatably mounted within the annular body7 3 of the hook upon an annular plate 30 which is rigidly secured to the hook body 3 and which lies in a plane normal to tl=e axis'or' rotation of the hook and the inner periphery of which is received in afraceway S1 cut around the periphery of the bobbin case 1. upper end Jr'ace a cup-shaped bobbin-receiving recess 32 in which is a central post 33 upon which is rotatably mounted a bobbin 311-. rfhe bobbin 3-1 place by means of a spring-held latch 35.

The bobbin case 1 is preyented from rotatr1`he bobbin case has in its top or is removably held in ing with the hook 2 by means of detent pins 40 and 41 which are arranged to engage circular recesses 42 and 43 drilled in the top of the bobbin case, one on each side of the bobbin-receiving recess 32. The pins 40 and 41 are formed upon the laterally extending arms 44 and 45 of two bell cranks 46 and 47. The arms 44 and 45 are substantially parallel and extend over the top of the bobbin case upon each side of the bobbin-receiving recess 32, leaving sullicient space between them so that the bobbin .can be readily taken out from' the top of the bobbin case. The bell cranks 46 and 47 are co-axially fulcrumed upon a shaft 50 which lies substantially in the plane of the flattop or upper end of the bobbin case 1. The shaft 50 is supported at its ends in ears 5l and 52 which are formed at the tops of upwardly extending posts 53 and 54 which are rigidly mounted in the frame 6 and are held by'means of nuts 55 threaded on their lower ends. /The shaft 50 is rigidly clamped in the ears 51 and 52 by means of pins 56, the sides of which are recessed to receive the shaft 50 and which are drawn upwardly to clamp the shaft by means of nuts 57. The hubs 58 and 59 of the bell cranks 46 and 47 are elongated to properly space the bell cranks apart and to atiord a long bearing which prevents the detent pins 40 and 41 from getting out of alinement with the recesses 42 and 43. The bell cranks 46 and 47 are given a limited oscillatory movement during each rotation of the hook by means of a cam 60 which is cut in the hub of the gear wheel 10. The cam 60 is engaged by cam rolls 61 and 62 mounted upon pins 63 and 64 which project from the ends of the downwardly extending arms 65 and 66 respectively of the bell cranks 46 and 47. The gear wheel 10 has the same number of teeth as the bevel gear 11 on the rotary hook and consequently the detent arms 44 and 45 are raised and lowered once during` each rotation. of the hook. The timing of the cam 60 is such that either one or the other of the detent pins 40 and 41 is in engagement with the bobbin case to hold it at all times against rotation, while the detent pin which would be in the path of the needle thread passing over the topof the bobbin case is withdrawn to allow the needle thread to pass. The hook is rotated in the direction indicated by the arrow in Fig. 1. After the loop of needle thread is taken from the barb of the needle, it is spread by the thread-receiving groove 8 and is carried about the bobbin case 1. The bottom leg of the loop is carried laterally (from right to left, as viewed in Fig. 3) across the unobstructed bottom end face of the bobbin case. The upper leg of the loop is'carried laterally (from rightto left, as viewed in Fig. 3) over the upper end face of the bobbin dass. The thread which passes over the upper face and backwardly,

is first carried across recess 43, the detent pin to permit it to pass and the detent pin 40 being advanced to hold the bobbin case from rotation. After the loop of thread has been distended to its max1mum and is being drawn in, the thread passes over the detentreceiving recess 42, the detent pin 40 being raised to permit its passage and the detent pin 41 being advanced into engagement with the bobbin case to `hold it from rotation.

In order to prevent the needle thread from being caught on the detent pins 40 and 41, thread guards and 71 are provided for the detent pins 40 and 41 respectively. The thread guards 70 and 7l are formed upon the ends of arms 72 and 73 which are integral with the tops of the posts 53 and 54 respectively and which extend substantially parallel with, but `iltside of, the detent arms 44 and 45. The thread guard 70 consists' of the two lingers 8O and 8l of of the arm 72. Y The lingers 8O and 81 extend about half way around the pin 40 and loosely embrace it. When the detent pin 40 is fully withdrawn from the bobbin case and into the thread guard, its free end is about at the level of the lower face of the thread guard 70, so that the threadcannot catch upon the end of the detent pin. The finger 81, as shown in Fig. 3, is thin so that it does not interfere with the downward movement of the arm 44. The ngers 8O and 8l extend substantially-in the direction in which the thread is moving as it is being pulled off from the bobbin case, so that there is no danger of the thread catching upon the free ends of the fingers. The thread guard 71 consists of the two fingers 82 and 83 of the forked end of the arm-73. The' fingers 82 and 83 extend substantially half way around and loosely embrace the, detent pin 41. When the detent pin 41 is fully withdrawn from the bobbin case and into the thread guard, its free end is in substantially the plane of the bottom of the thread guard so that the thread is prevented from catching on they pin. Since the thread which passes under the detent piu 41 is passing to the left as viewed in Fig. 3, in or-V der to prevent the thread from catching on the ends of the fingers 82 and 83, the linger 82 is short and the finger 83 is carried about half way across the front of the pin 41, as viewed in Fig. 3. The fingers 82 and 83 thus entend in the general direction in which the thread is moving so that the thread passes away from the free ends of these lingers and cannot be caught upon them. The finger 82 wlhich extends under the detent arm 45 is, li ze with the movement, of the arm 45.

vWhile the preferred embodiment of the present invention has been specifically illustrated and described, the present invention is the detent-receiving 41 being withdrawn the forked endA the finger 81, thin so as not to interfere mantas noeiimited te; its illurated embodiment but may' be embodied in other constructions within the scope of the invention as set iorth in the following claims. Y

1. A loch stitch sewingmachine having, in combination, a rotary hook, mechanism for driving the hook, a discoidal bobbin case about which the loop of thread is cast by the hook rotatably mounted in the hoch and having a.- cup-shaped bobbin-receiving recess in im end face and-two detent-receivt recesses: inthe same face one on each vside or thebobbin-receiving recess, means for holding the bobbin case from rotation comprising two detent arms extending laterally over the end of the bobbin case upon each side of the bobbin-receiving recess and having detent pins for engaging the detentreceiving recesses in the bobbin case, mechanism for oscillating the arms to alternately advance and withdraw the detent pins so as to permit the needle thread to pass about the bobbin case, and means for preventing the needle thread from being caught on the detent pins comprising two ixed arms extending laterally over the end of the bobbin case and having at their free ends thread guards which loosely embrace the detent pins and into which the detent pins are withdrawn.

2. A loclr stitch sewing machine having, in combination, a rotary hook, mechanism for driving the hook, a discoidal bobbin case about which the loop of thread is cast by the hook rotatably mounted in the hook and havinga cup-shaped bobbin-receivng recess in its end face. and two detent-receiving recesses in the same face one on each side of the bobbin-receiving recess, means for holding the bobbin case Jfrom 'rotation comprising two detent arms extending laterally over the end of the. bobbin case upon each side of the bobbin-receiving recess and having detentA pins for engaging the detent-V receivmg recesses in the bcbbin case, mechanism for oscillating the arms to alternately advance and withdraw the detent pins so as to permit the needle thread to pass about the bobbiii case, and thread guards for preventing the needle thread .from being caught on the detent pins. t

dan lock stitch sewing machine having, in combination, a rotary hook, mechanism *for driving the hook, a discoidal bobbin case about which' the loop of thread is cast by the hook rotatably mounted in the hoch and having a cup-shaped bobbin-receiving recess .in its end face and two detent-receiviiig recesses in the saine face one on each side of the bobbin-receiving recess, means torholding the bobbin case from rotation ycompris,- ing two substantially parallel detent arms extending laterally over the end of the bobbin case upon each side of the bebbin-reeeivin recess and having detent ins for engaging the detent-receiving recesses in the bohbin case, mechanism for oscillating the arms to alternately advance and withdraw the detent pins so as to permit` the needlethread `to pass about'the bobbin case, and means .for preventing the needle 'thread from being caught on the detent pins comprising two xed arms extending laterally over the end of the bobbin case and having their free ends forked to form thread guards which consist ot fingers extending in the general direction of movement of the thread and loosely embracing the detent pins and into which the detent pins are withdrawn.

el. A lock stitch sewing machine having,

in combination, a rotary hook, mechanism for driving the hook, a'discoidal bobbin case about which the loop ofltliread is cast by the hook rotatably mounted in the hook and having a cup-shaped bobbin-receiving recess in its end face and two datent-receiving recesses in the same ace one on each side of the bobbin-receiving recess, means for holding the bobbin case from rotation comprising tvvosubstantially parallel detent arms extending laterally over the end of the bobbin case upon each side of the bobbin-receiving recessand having detent pins extending toward the end face of the bobbin in directions substantially normal to the end face for engaging the datent-receiving recesses in the bobbin case, and mechanism for oscillating the arms to alternately 4advance andwithdraw the detent pins so as to permit the needle thread to pass about the bobbincase.

5. A loch stitch sewing machine having, in combination, a rotary hook, mechanism i'or driving the hook, a discoidal bobbin case about which the loop of thread is cast by the hook rotatably mounted in the hook and having a cup-shaped bobbin-receiving recess in its end face and two datent-receiving recesses in the same tace one'on each side of the bobbin-receivin g recess, means for holdin g the bobbin case from rotation comprising two bell cranks having substantially parallel arms extending laterally over the end of the bobbin case upon each side of the bobbinreceiving recess and having detent pins for engaging the dctent-receiving recesses in the bobbin case, and mechanism located out of the plane of the end face of the bobbin case and engaging the other arms of the bell cranks for oscillating the bell cranks to alternately advance Yand withdraw the detent pinsso as to permit the needle thread to pass about the bobbin case.

6. A loch stitch sewing machine having,

llU

hook and having a bobbin-receiving recess in 1ts end face and two detent-receivmg recesses in the same face one on each side ot the bobbin-receiving recess, posts on the hook supporting frame, a shaft mounted on said posts, two detent arms fulcrumed on said shaft and extending laterally over the end otl the the bobbin-receiving recess and having at their ends detent pins for engaging the detent-receiving recesses in the bobbin case, and mechanism connected with the hook driving mechanism for oscillating the arms to alternately advance and withdraw the detent pins'so as to permit the needle thread to pass about the bobbin case.

T. A lockstitch sewing machine having, in combination, a rotary hook, u frame upon which the hook is rotatably supported,

mechanism for driving the hook including bevel gear teeth on the hook, av bevel gear wheel mounted on the -trame and meshing 'with the gear teeth on the hook and means for driving the bevel gear wheel, a discoidal bobbin case about which the loop of thread is cast by the hook rotatably mounted in the hook and having a bobbin-receiving recess in its end face and two detent-receiving recesses in the same face one on each side' of the bobbin-receiving recess, means for holding the bobbin case from rotation comprising two bell crank levers fulcrumed on the hook supporting frame inl approximately the, plane ot the end face ot the bobbin 1.case in which the detent-receiving recesses are ,and having substantially parallel arms extending laterally over the top ot' the bobbin' :ase upon each side of the bobl'iin-recciving recessand having detent pins on the tree ends of the detent arms for engaging the detent-receiving recesses in the bobbin case` a.

cam co-axial with the bevel gear teeth and connected with the bell cranks for oscillating them to alternately advance and withdraw the detcnt pins so as to permit the needle thread to pass about the bobbin case` and means for preventing the needle thread from catchingr upon the detent pins enmprising two fixed arms on the hook supporting trame extending laterally over the end tace. of the hobbin case. and having at their 'tree ends thread guards which loosely cmbrace the (let'ent pins and into which the detent pins are withdrawn.

8. A lock stitch sewing machine having. in combination. a rotary hook. awfraine. upon which the' book is rotatably supported. mechanism for driving vthe book including bevel gear teeth on the. hook. a bevel gear wheel mounted ou the -lrame and meshing with the. gear teeth on the hook and means' for driving the bevel VQcar wheel. a discoidal bobbin case about which the loop of thread is cast. by the hook rotatably mounted in the hook and havingl a bobbin-rcceiving yrecess bobbin case one on each side or'l in its end tace and two detent-receivingrec'esses in the same face one on each side of the bobbin-rcceiving recess, means for holding the bobbin case from rotation comprising two bell crank levers fulcrumed on the hook supporting frame in approximately the plane ot thc end face of the bobbin case in which the dctent-receiving recesses are and having substantially parallel arms ex tending laterally over the top of the bobbin case upon each side of the bobbin-receiving recess and having; dctcnt pins on the free ends oi the detcnt arms for engaging the detent-rcccivingl recesses in the bobbin case'. and a cam co-axialwith the bevel gear teeth and connected with the bell cranks for oscillating them to alternately advance and withdraw the detentpins so as to permit the needle thread to pass about the bobbin case.

9. A lock stitch sewing machine having, in combination. a rotar)7 hook, an oscillating frame on the top of which the hook is rotatably supported. mechanism for driv` ing the hook including bevel gear teeth on the hook. a bevel gear mounted on the frame below the hook and meshing with the gear teeth ou the hook and means for driving the bevel gear-wheel. a discoidal bobbin case about which the loop of needle thread is east by the hook rotatably supported in the hook and having a bobbin-receiving recess in its upper end tace and two detent-rccei y'ing' recesses in the same tace one on each side ot the bobbin-rcceiving recess. upwardly extending posts on the hook supporting trame. a shat't extending between said posts. two bell crank levers ful'crumed on the shattand having arms extending laterallv over the top ot the bobbin case upon each side of the bobbinreceivingrccess and having dctentpins at the tree ends ot' the arms tor engaging the detent-receiving recesses in the bobbin case to hold the bobbin case trom rotation. said bell crank levers having downwardly extending arms terminating at the hub ot the bevel `ear wheel. a cam on the hub ot the bevel gear wheel connected with the downwardly extending arms oii the bell crank levers for oscillating them to alternately advance and withdraw the dctent pins so as to permit the 4 tor drivingv the hook. a bobbin case about which the loon ot thread is cast bv the hook rotaiablv mounted in the hook and having defeat-recelving recesses 1n one of its end f ward the end face faces, means for holding the bobbin case from rotation comprising detent arms extending laterally over the end of the bobbin case and having detent pins extending toof the bobbin in directions substantially no1-mal to i-"m' engaging the detent-reeeiving recesses in the b'obbin case, and mechanism fdp osthe endface cillating the arms to alternately advance bn case.

LAURENCE E. TOPHAM.

Witnesses:

CHESTER E. ROGERS, NRUTH E. W'ABD. 

